A unique solar lineshift analyzer described by Rust, Burton and Leistner (1986) has been used at the Sacramento Peak Observatory to study solar oscillations. Operation of this “Stablized Solar Analyzer” (SSA) depends on the electro-optic effect in crystalline lithium niobate, the substrate of the solid Fabry-Perot etalon. Voltage on the etalon shifts the passband by ∼ 4.5 × 10−4 Å/V. The etalon has a passband of 0.175 Å at 6102.7 Å. The stabilization system uses a tunable diode laser to relate the Fabry-Perot passband to the D2 line of atomic Cs 133, at 8521.46 Å. This system reduced instrumental noise to less than Δλ/λ = 10−9 over a six-hour interval.